My advice is not to add any more complications or delays than are strictly necessary.
I've had clients (purchasers) shy away from Executors sales because of the delays with Probate.
Purchasers want to close and get in as soon as possible. They are terrified about interest rates and uncertainty.
The family member, who may have their own very good reasons for wanting to stay on, needs to understand that if they do want to stay on, that that makes the transaction less attractive to a purchaser.
In the overall scheme of things, the extra delay would not be normal or acceptable.
mf